WorksheetsSynthetic Antibacterial (Nitrofurans and Antituberculars)
Total questions: 59
Worksheet time: 53mins
First nitroheterocyclic compound to be introduced into chemotherapy.
(a)
Nitrofurans are derivatives of 4-nitro-3-furaldehyde, formed on reaction with the appropriate hydramine or amine derivative.
True
False
An antiprotozoal nitrofuran used to treat trypanosomiasis and leishmaniasis
(a)
A nitrofuran with an azole group used as an amoebacide
(a)
MAjor adverse effect of nitrofurans
(a)
Nitrofurans antibacterial property is only present when the nitro group is in __________ of the ring
4 position
5 position
3 position
6 position
The mechanism of action of nitrofurans is trough the reduction of the nitro group via the action of the enzyme nitrofuran reductase followed by the formation of reactive intermediates or radicals which causes damage or disruption of the following:
Ribosomal proteins
DNA and its inhibition
RNA
Proteins
Cell wall and its sythesis
For burns and infections involving skin grafts
(a)
Oral treatment for bacterial or protozoal diarrhea
(a)
Nitrofuran orally administered for UTI. Its microcrystalline form improves GI tolerance without interfering with oral absorption.
(a)
Methenamine is prepared by evaporating a specific combination of the solution to dryness. What is the components of that solution?
Formaldehyde
Strong ammonia water
Ammoniated lime
Acetic acid
The antibacterial activity of methenamine depends on the liberation of formaldehyde. This can be enhanced by acidifying the medium using what of the following
Sal ammoniae
Ammonium chloride
Sodium biphosphate
Potassium bisphosphate
Methenamine is ineffective against microorganisms containing (a) . An enzyme that can degrade urea to ammonia.
Nitrofuran used for chronic UTI
(a)
Acidification of urine to a pH of (a) for optimal delivery of methanamine.
The salt form of methenamine.are used as
(a)
Mandelamine
(a)
Hiprex
(a)
Alleviate pain and discomfort caused by UTI and concentrates in the urine through local analgesic effect on the mucosa of UT. Also known as a urinary analgesic.
(a)
Phenazopyridine is combined with
Paracetamol
Ammonium chloride
Azo-gantrisin
Urobiotic
Phenazopyridine preparations color the urine similar to Rifampicin, red-orange. To prevent staining (a) is used.
Do Mycobacterium tuberculosis live inside the macrophages and lysosomes
True
False
The causative agents for tuberculosis are gram-positive acid-fast bacillus (has mycolic acid on its cell wall)
True
False
Organs and systems susceptible to tuberculosis
Bones and Intestine
Lymph Nodes
Kidney
Tubercular Meningitis
Breast
Management of Tuberculosis
(a)
Aim of tuberculosis therapy, treatment must be for
longer period because the response to chemotherapy
is slow due to
Slow rate of growth
Due to ineffective drugs
Intracellular location of the infection (inside macrophages and lysosomes)
Large number of actively multiplying bacteria must be killed
Development of rapid resistance
Best treatment for a large number of actively multiplying bacteria must be killed
(a)
Persisters are semi-dormant bacilli that metabolize slowly, should be treated with
(a)
Why combination therapy is given in TB
single agents are not enough to treat mild infections
reduce the toxicity of individual drugs
drugs forms synergism to one another to increase their activity against the infectious agents
To broaden the spectrum
prevent the emergence of resistance
First-line agents for TB
(a)
a single agent as first-line treatment for TB
(a)
Which of the following is not a 2nd line agent for TB
ciprofloxacin, ethionamide,
Aminoglycosides, paminosalicylic acid (PAS)
levofoxacin, cycloserine
rifabutin, capreomycin
Rifamycin, echiocandins
The first 2 months of the TB therapy are composed of the RIPE, however in the last 4 months a drug is removed to reduce the incidence of optic neuropathy. What drug is this?
(a)
Which among are the prophylactic doses for TB using Isoniazid
300mg/day
900mg twice weekly for 6 to 12 months in case of immunocompromised patients
5mg/kg/day
600mg twice weekly for 6 to 12 months in case of immunocompromised patients
350mg/day
Prophylaxis for the patients who are unable to take isoniazid; have close contact with a case of active TB caused by an isoniazid resistant Rifampicin-susceptible strain
(a)
Toxicity includes insomnia, peripheral neuropathy, and hepatotoxicity.
(INH)
(a)
safest, most potent, and effective against all forms of M. tuberculosis; Bactericidal
(a)
An antitubercular is readily absorbed from the GIT and does not bind with the plasma protein. It will undergo extensive distribution in the tissue and body fluids.
(a)
2nd line agent for TB as a treatment for INH-resistant cases. It can cause GI intolerance, visual disturbances, and hepatotoxicity.
(a)
first line agent in short term TB
(a)
synthetic analogue of nicotinamide
(a)
Effective in low pH environment as it can kill TB bacilli in acidic pH up to 5.5 including intracellular infection, within the macrophage and lysosome. It also penetrates inflamed meningesHowever, cannot kill TB bacilli in the blood because of high pH.
(a)
Stereospecific to active against dividing mycobacteria antitubercular
(a)
Mechanism of action of ethambutol
Prevents incorporation of PABA in dehydrofolic acid molecule
Inhibition of the incorporation of mycolic acid into the cell wall of the microorganisms
prevents the synthesis of cross-linking peptide in the formation of bacterial cell walls
Inhibits the synthesis of Arabinogalactan which is an essential component of the mycobacterial cell wall.
Mechanism of action of cycloserine
Prevents incorporation of PABA in dehydrofolic acid molecule
Inhibition of the incorporation of mycolic acid into the cell wall of the microorganisms
prevents the synthesis of cross-linking peptide in the formation of bacterial cell walls
Inhibits the synthesis of Arabinogalactan which is an essential component of the mycobacterial cell wall.
Mechanism of action of aminosalicylic acid
Prevents incorporation of PABA in dehydrofolic acid molecule
Inhibition of the incorporation of mycolic acid into the cell wall of the microorganisms
prevents the synthesis of cross-linking peptide in the formation of bacterial cell walls
Inhibits the synthesis of Arabinogalactan which is an essential component of the mycobacterial cell wall.
True about the toxicity of ethambutol, except:
Retrobulbar optic neuritis (most common)—loss of visual acuity, blue-green color blindness, and blindness
Can be given to children
Causes increase in urine uric acid (Hyperuricemia)
Hypersensitivity is common
Mechanism of action of aminosalicylate sodium
Prevents incorporation of PABA in dehydrofolic acid molecule
Inhibition of the incorporation of mycolic acid into the cell wall of the microorganisms
prevents the synthesis of cross-linking peptide in the formation of bacterial cell walls
Inhibits the synthesis of Arabinogalactan which is an essential component of the mycobacterial cell wall.
A basic red dye that exerts slow bactericidal effect on M. leprae and has an anti-inflammatory and immune-modulating effects
(a)
Treatment for skin lesions caused by M. ulcerans. However also causes skin pigmentation, ichthyosis, dryness, rash, pruritus, and severe GI disturbances (similar to ethionamide).
(a)
Prophylaxis of disseminated MAC in AIDS patients
(a)
Semisynthetic derivative of Rifamycin produced by S. mediterranei
(a)
An antitubercular effective against Neisseria meningitidis
(a)
Rifampin / rifampicin is an enzyme
Inducer
Inhibitor
When rifampicin is taken along with this drug it inactivates APAP
(a)
Color or tint of urine, stool, saliva, tears, skin after taking rifampicin
(a)
Cycloserine is isolated from which of the following agents
Strep. orchidaceus
Strep. lavendulus
Strep. garyphalus
Strep. mediterranae
Strep. rimosus
An aminoglycoside, strongly basic cyclic peptide isolated from Strep. capreolus. Second line agent and an alternative to streptomycin.
(a)
Which among is correctly paired with their corresponding toxicities, except:
Isoniazid - optic neuritis
Pyrazinamide - Cholestatic jaundice + renal toxicity + Flu like syndrome
Pyrazinamide - Hepatotoxicity + Hypeuricemia
Rifampicin - Cholestatic jaundice + renal toxicity + Flu like syndrome
Ethambutol - optic neuritis
